Kabul, Afghanistan — Up to 17 Afghans are dead and 5 injured after a US soldier left his base in the south of Afghanistan and attacked at least three local homes on Sunday. International military officials have detained the US soldier and are working with Afghan authorities to investigate the incident.

“Initial reports indicate that the shooter acted alone and that this did not occur in conjunction with or during an ISAF operation,” says US Air Force Capt. Justin Brockhoff, an ISAF spokesman. “It is not clear at this time what the individual’s motives were and we do not know if the individual had any ties or issues with those who were wounded.”

Tensions are already high between NATO forces and Afghans after the burning of several Qurans on a US base led to a week of violent protests last month. The shooting may increase Afghan anger toward Western troops here, however, Afghans have traditionally not responded with violence or widespread protest to such incidents, largely viewing this sort of behavior as an all too familiar byproduct of war. Past incidents included the deliberate killing of Afghan civilians by a rogue Stryker platoon and some Marines urinating on Taliban corpses.

“It gives us the message that the American soldiers are not under the control of their generals and these American generals have failed to manage them,” says Abdul Rahim Ayobi, a member of Parliament from Kandahar. “It will definitely raise the hatred of Americans among Afghans.”

Sunday’s shooting occurred in Afghanistan’s restive Panjwayi district in Kandahar Province. Initial reports indicate that soldier walked off base around 3:00 am and attacked several families while they slept. Among Afghans in the area, the scope of the attack has led to speculation that the shooter may have had an accomplice, but these reports remain unconfirmed.

Haji Fazal Mohammad, a tribal elder in Panjwayi who visited two of the homes, says that in one home where 11 people were killed, three women and four children were among the dead.

The shooter apparently tried to set fire to the house, says Mr. Mohammad, leaving several of the bodies burned. Among the dead Mohammad saw, he says that all appeared to have been killed by gunfire. Villagers in the area staged a small protest with the bodies, but the group disbanded upon the urging of local elders who warned a demonstration could create more problems for the village.

The case could strengthen Afghan resistance to a long-term basing agreement with the US that would keep a smaller number of American forces in Afghanistan beyond the 2014 withdrawal deadline. The US is seeking immunity from the Afghan legal system for American troops, a sticking point that may grow more difficult for Afghan leaders to back down on following today's attack. The immunity issue scuppered a similar treaty the US had sought in Iraq.

Civilian causalities have also long been an issue in Afghanistan. According to UN reports, international forces have succeeded in reducing the amount of civilian deaths their troops cause each year, but such an incident is likely to bring the issue to the forefront of the Afghan political debate.

“It definitely raises the issue of civilian casualties. They have always been a hot issue for the Afghan government and they were always asking the US forces to be careful in their operations not to harm the civilians. This is another example of the behavior of foreign soldiers who burned the Quran and now they are killing civilians. It will make the issue even bigger,” says Nazeefa Zaki, member of parliament from Kabul and a former police general.

Still, speaking about the US shooter now in custody, she adds, “I mostly I think that this person was not normal … maybe he has psychological problems or maybe he was drunk, but I’m 100 percent certain he was not in a normal condition.”